/*
	* SPI testing utility (using spidev driver)
	*
	* Copyright (c) 2007 MontaVista Software, Inc.
	* Copyright (c) 2007 Anton Vorontsov <avorontsov@ru.mvista.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License.
	*
	* Cross-compile with cross-gcc -I/path/to/cross-kernel/include
	*/
	
#include <stdint.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/spi/spidev.h>
	
#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
	
static void pabort(const char *s)
{
		perror(s);
		abort();
}
	
static const char *device = "/dev/spidev0.0";
static uint8_t mode;
static uint8_t bits = 8;
static uint32_t speed = 500000;
static uint16_t delay = 0;
	
static void transfer(int fd)
{
		int ret;
		uint8_t tx[] = {
			0x00, 0x00, 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 
			0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07,
			0x00, 0x08, 0x00, 0x09, 0x00, 0x0a, 0x00, 0x0b,
			0x00, 0x0c, 0x00, 0x0e, 0x00, 0x0d, 0x00, 0x0f,
		};
		uint8_t rx[ARRAY_SIZE(tx)] = {0, };
		struct spi_ioc_transfer tr = {
				.tx_buf = (unsigned long)tx,
				.rx_buf = (unsigned long)rx,
				.len = ARRAY_SIZE(tx),
				.delay_usecs = delay,
				.speed_hz = speed,
				.bits_per_word = bits,
		};
	
		ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
		if (ret == 1)
				pabort("can't send spi message");
	
		for (ret = 0; ret < ARRAY_SIZE(tx); ret++) {
				if (!(ret % 6))
						puts("");
				printf("%.2X ", rx[ret]);
		}
		puts("");
}
	
static void print_usage(const char *prog)
{
		printf("Usage: %s [-DsbdlHOLC3]\n", prog);
		puts(" -D --device device to use (default /dev/spidev1.1)\n"
				" -s --speed max speed (Hz)\n"
				" -d --delay delay (usec)\n"
				" -b --bpw bits per word \n"
				" -l --loop loopback\n"
				" -H --cpha clock phase\n"
				" -O --cpol clock polarity\n"
				" -L --lsb least significant bit first\n"
				" -C --cs-high chip select active high\n"
				" -3 --3wire SI/SO signals shared\n");
		exit(1);
}
	
static void parse_opts(int argc, char *argv[])
{
		while (1) {
				static const struct option lopts[] = {
						{ "device", 1, 0, 'D' },
						{ "speed", 1, 0, 's' },
						{ "delay", 1, 0, 'd' },
						{ "bpw", 1, 0, 'b' },
						{ "loop", 0, 0, 'l' },
						{ "cpha", 0, 0, 'H' },
						{ "cpol", 0, 0, 'O' },
						{ "lsb", 0, 0, 'L' },
						{ "cs-high", 0, 0, 'C' },
						{ "3wire", 0, 0, '3' },
						{ "no-cs", 0, 0, 'N' },
						{ "ready", 0, 0, 'R' },
						{ NULL, 0, 0, 0 },
				};
				int c;
	
				c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR", lopts, NULL);
	
				if (c == -1)
						break;
	
				switch (c) {
				case 'D':
						device = optarg;
						break;
				case 's':
						speed = atoi(optarg);
						break;
				case 'd':
						delay = atoi(optarg);
						break;
				case 'b':
						bits = atoi(optarg);
						break;
				case 'l':
						mode |= SPI_LOOP;
						break;
				case 'H':
						mode |= SPI_CPHA;
						break;
				case 'O':
						mode |= SPI_CPOL;
						break;
				case 'L':
						mode |= SPI_LSB_FIRST;
						break;
				case 'C':
						mode |= SPI_CS_HIGH;
						break;
				case '3':
						mode |= SPI_3WIRE;
						break;
				case 'N':
						mode |= SPI_NO_CS;
						break;
				case 'R':
						mode |= SPI_READY;
						break;
				default:
						print_usage(argv[0]);
						break;
				}
		}
}
	
int main(int argc, char *argv[])
{
	int ret = 0;
	int fd;

	parse_opts(argc, argv);
	fd = open(device, O_RDWR);
	if (fd < 0)
			pabort("can't open device");

	/* spi mode */
	ret = ioctl(fd, SPI_IOC_WR_MODE, &mode);
	if (ret == -1)
			pabort("can't set spi mode");
	ret = ioctl(fd, SPI_IOC_RD_MODE, &mode);
	if (ret == -1)
			pabort("can't get spi mode");

	/* bits per word */
	ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
	if (ret == -1)
			pabort("can't set bits per word");
	ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
	if (ret == -1)
			pabort("can't get bits per word");

	/* max speed hz */
	ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
	if (ret == -1)
			pabort("can't set max speed hz");
	ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
	if (ret == -1)
			pabort("can't get max speed hz");

	printf("spi device: %s\n", device);
	printf("spi mode: %d\n", mode);
	printf("bits per word: %d\n", bits);
	printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
	while(1)
	{
		transfer(fd);	
	}

	close(fd);

	return ret;
}